Display device

Abstract

To provide a display device that makes speckles on a screen difficult to be visually recognized and allows an observer to easily observe an image projected on the screen easily. A display device includes a projector that emits coherent light, a screen that projects the coherent light emitted from the projector, and a first optical system that guides transmitted light or diffused light of the screen to an observing direction of an observer, and allows an observer to observe a real image or a virtual image of an image projected on the screen. The screen includes a plurality of particles including a first portion and a second portion, a particle layer having a plurality of particles, electrodes for applying a voltage to the particle layer to generate an electric field for driving the particles of the particle layer.

1 . A display device comprising:
 a projector that emits coherent light;   a screen on which the coherent light emitted from the projector is projected; and   a first optical system that guides transmitted light or diffused light of the screen to an observing direction of an observer and allows an observer to observe a real image or a virtual image of an image projected on the screen,   wherein the screen comprises   a plurality of particles each comprising a first portion and a second portion,   a particle layer comprising the plurality of particles, and   an electrode that generates an electric field for driving the particles of the particle layer when a voltage is applied to the particle layer.   
     
     
         2 . The display device according to  claim 1 , wherein the first optical system comprises a half mirror that partially transmits and reflects the transmitted light or the diffused light of the screen, and allows the observer to observe the virtual image of the image projected on the screen. 
     
     
         3 . The display device according to  claim 1 , wherein the first optical system comprises a concave mirror that reflects the transmitted light or the diffused light of the screen, and allows the observer to observe the real image of the image projected on the screen. 
     
     
         4 . The display device according to  claim 1 ,
 wherein the screen is of a transmissive type,   the display device further comprises a second optical system arranged at a position between the screen and the first optical system where the coherent light transmitted through the screen from the projector is not directly incident, and   the first optical system guides the coherent light that has passed through the second optical system to an observing direction of the observer.   
     
     
         5 . The display device according to  claim 1 , wherein the screen comprises a light diffusing layer arranged close to the particle layer. 
     
     
         6 . The display device according to  claim 5 , wherein the screen comprises a light direction changing member arranged close to a side opposite to a side on which the light diffusing layer of the particle layer is closely arranged to change a traveling direction of incident light. 
     
     
         7 . The display device according to  claim 1 , wherein the screen comprises two light diffusing layers arranged on both sides of the particle layer interposed between the two light diffusing layers. 
     
     
         8 . The display device according to  claim 5 , wherein the screen comprises a light absorbing layer that is arranged close to the light diffusing layer and absorbs light in a predetermined wavelength range. 
     
     
         9 . The display device according to  claim 5 ,
 wherein the screen comprises:   a lens array arranged between the particle layer and the light diffusing layer; and   a black matrix arranged between the lens array and the light diffusing layer.   
     
     
         10 . The display device according to  claim 2 ,
 wherein the screen is of a transmissive type,   the display device further comprises a second optical system arranged at a position between the screen and the first optical system where the coherent light transmitted through the screen from the projector is not directly incident, and   the first optical system guides the coherent light that has passed through the second optical system to an observing direction of the observer.   
     
     
         11 . The display device according to  claim 3 ,
 wherein the screen is of a transmissive type,   the display device further comprises a second optical system arranged at a position between the screen and the first optical system where the coherent light transmitted through the screen from the projector is not directly incident, and   the first optical system guides the coherent light that has passed through the second optical system to an observing direction of the observer.   
     
     
         12 . The display device according to  claim 2 , wherein the screen comprises a light diffusing layer arranged close to the particle layer. 
     
     
         13 . The display device according to  claim 3 , wherein the screen comprises a light diffusing layer arranged close to the particle layer. 
     
     
         14 . The display device according to  claim 4 , wherein the screen comprises a light diffusing layer arranged close to the particle layer. 
     
     
         15 . The display device according to  claim 2 , wherein the screen comprises two light diffusing layers arranged on both sides of the particle layer interposed between the two light diffusing layers. 
     
     
         16 . The display device according to  claim 3 , wherein the screen comprises two light diffusing layers arranged on both sides of the particle layer interposed between the two light diffusing layers. 
     
     
         17 . The display device according to  claim 4 , wherein the screen comprises two light diffusing layers arranged on both sides of the particle layer interposed between the two light diffusing layers. 
     
     
         18 . The display device according to  claim 6 , wherein the screen comprises a light absorbing layer that is arranged close to the light diffusing layer and absorbs light in a predetermined wavelength range. 
     
     
         19 . The display device according to  claim 7 , wherein the screen comprises a light absorbing layer that is arranged close to the light diffusing layer and absorbs light in a predetermined wavelength range. 
     
     
         20 . The display device according to  claim 6 ,
 wherein the screen comprises:   a lens array arranged between the particle layer and the light diffusing layer; and   a black matrix arranged between the lens array and the light diffusing layer.